Querying nested array fields with match operator in Sanity

The issue with your GROQ query is in how you're filtering on a nested array field. When you write *[variants[].sku match "*test*"], GROQ interprets this in a way that doesn't work as expected for filtering documents.

The problem is that variants[].sku creates a projection that extracts all SKU values from the variants array, but you can't directly use this projection syntax in a filter condition. Instead, you need to check if any element in the array matches your condition.

Here are the correct ways to query this:

Option 1: Using the in operator (recommended for exact/pattern matches)

*["test1" in variants[].sku]

This checks if the string "test1" exists anywhere in the array of SKU values.

Option 2: Using match with a filter on the array

*[count(variants[sku match "*test*"]) > 0]

This filters the variants array to only those where sku matches your pattern, counts them, and returns documents where at least one match exists.

Option 3: More explicit version with document type

*[_type == "yourDocumentType" && count(variants[sku match "*test*"]) > 0]

Why your original query didn't work:

The syntax variants[].sku is a projection operator that extracts values, not a filter. When you try to use it directly in a filter like *[variants[].sku match "*test*"], GROQ doesn't evaluate it as "any variant's sku that matches", but rather tries to apply the match to the projection result itself, which doesn't work in a filter context.

Best practice:

For substring matching in nested arrays:

*[count(variants[sku match "*test*"]) > 0]

For exact matching in nested arrays:

*["test1" in variants[].sku]

The key difference is that inside the array filter variants[...], you're working with individual array items, so you directly reference sku without the [] operator. The [] operator is only used when projecting/extracting values, not when filtering within the array itself.